UPDATE, 4:50 PM: Ratings predictions often come back to bite you, like Simon Cowell’s projection for a 20 million-plus premiere of The X Factor on Fox before the show opened to about half of that, 12.5 million viewers, in 2011.

But that was not the case with the CW president Mark Pedowitz, who two months ago at TCA was asked to predict the ratings performance for Supergirl in its move from CBS. “It won’t do as well as it did on CBS, even at the end of the season. But whatever it does, I anticipate it will be our No. 1 or No. 2 show behind The Flash,” he said back then. Flash forward to last night, when the second season of Supergirl, featuring her famous caped cousin, drew 3.1 million viewers and 1.1 in 18-49 (Live+Same Day) in its first original telecast on the CW. That was on par with the L+SD season premiere of The Flash (3.1 million) and a close No. 2 behind The Flash (1.3) in the demo for the second-biggest opener on the network this fall. And yes, as expected, Supergirl was off its CBS delivery, even later in the season when ratings tapered off, including the Season 1 finale (1.3, 6.1 million).

Supergirl lifted the CW’s Monday 8 PM time slot, delivering the network’s largest audience in the hour in nearly eight years (Gossip Girl on 12/1/08), the highest 18-49 rating in nearly six years (90210 on 12/6/10), and highest rating in adults 18-34 (0.9) in almost five years (11/21/11). Supergirl was also the CW’s highest-rated show ever in its time period in men 18-49 (1.2).

The CW used the solid Supergirl debut to get extra sampling for new comedy No Tomorrow, which is not breaking out so far. Its pilot scored a pretty modest 0.2 in the demo for its encore behind the superhero drama.

New NBC drama Timeless (1.4 after a downward adjustment in the finals) was down 22% from its premiere with identical lead-in, The Voice (2.9, even with last Monday). That is steeper than that 16% Week 2 decline for Blindspot in the time slot last fall.

New CBS comedy Kevin Can Wait (2.1) held steady, off by a 0.1 in Week 4 after that worrisome 0.5 Week 3 drop. Its lead-in, The Big Bang Theory (3.4 after upward adjustment in the finals), also was off by a tenth from last week.

Utility player 2 Broke Girls (1.7 from 9-10 PM) also showed sturdiness after being moved again, opening its sixth season up a tenth from its last season premiere in the Thursday 9:30 PM slot behind Mom.

However, Scorpion is not handling its scheduling move as well. After opening its third season in the new 10 PM slot with s series-low-tying 1.5 in 18-49, the action drama fell 0.2 in Week 2 to a new low mark of 1.3.

Fox’s Gotham (1.1) and Lucifer (1.0) both were relatively on par with last week.

ABC’s fast nationals were inflated by an NFL preemption. In the finals, Dancing With The Stars drew 1.6 in 18-49. New drama Conviction (0.8) slipped a tenth from its underwhelming debut.